Acoustical control of charge movement in an organic semiconductor

We show experimentally the directional acoustic charge transport of optically generated charge carriers in an organic semiconductor at room temperature by surface acoustic waves (SAWs) generated on a lithium niobate substrate utilizing an easy and straightforward structure consisting of two identical interdigital transducers (IDTs) and a corresponding collector diode facing each IDT. An orthogonal arrangement of the two IDTs has been used to analyse the impact of SAW drag force on the charge carriers by interacting two SAWs. In addition, we show the frequency dependency of the acoustic dragging force on charge carriers by orthogonally interacting SAW beams of different frequencies. This relation provides the idea of using one or more SAWs to achieve an acoustic manoeuvring of charge carrier transport. The diagonal propagation of the carriers through orthogonal SAW beams of the same frequencies was also verified experimentally, thus giving rise to the possibility of an acoustic charge transfer device that may be employed as a fundamental gate for information processing based on the charge transport with the help of SAW.